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  • Who wants to play in my sandbox?

    Hi everyone! I am tackling this two year old project again and weighing my options. Any insight will be appreciated and I hope I can share some insight.

    So here we go. I'm looking to go Solar on my 1500 Sq ft. Living area in central Missouri and want to do it right at the best deal. I know putting it in myself would be the most cost effective but I don't want too hassle with the warranty so here we are calling every solar company, taking bids and going over ideas. So far it's been a little frustrating as its pretty much like dealing with car salesman that want to you to close on the car "they have" and have all these "cool and groovy" incentive plans. All I want is to replace my electric bill with something tangible nothing more nothing less.

    So lets start a non biased idea center here .

    OK so here's the nitty gritty on average I used 2,137 Kwh a month last year. So I'm looking at a 16-19 KW System.

    I've been quoted

    Simple Solar $44,000 for 18.76 KW, Has a "cool groovy" we pay the first 18 payments plan. So I guess $40,000.00

    Missouri (Sun Solar) $50,000 for a 17.8 KW He threw a Lease idea at me after I kinda mocked his price. But they are used the most in my area and have a solar flower at the Bank I use so I guess they get bonus points for having that.

    *SES $38,208 for a 19.2KW no financing so +4% at my bank +closing cost.

    and Solera that broke it down doe $3.45 per watt.... sorry I was less interested in this offer due to his pushiness to a ground mount which I know will be more efficient but more of a hassle for me and my wife.

    So ya numbers all over the place and really it shows me that the efficiency is really going to play a huge factor.

    ...and no we won't qualify for the Tax incentive and we didn't the last two years so ya that's why this sucks so hard but I'm wanting to invest now!!!

    Here's the fun part. I have a 50 x 30 shed 90 ft from the tree infested house that all ready has power to it and sits along the buried power line to the house from the pole the meter is on the house.

    It was built 90 degrees wrong though ugh. Its got an East West pitched roof.

    Soooooo... that's where the really efficient 14Kw ground mount guy was. Saying its a waste of panels and he thought me mowing around it and the wife hitting it with the car would be a much better funner option.

    So let me know what your guys thoughts are.

    I'm now thinking about putting a couple winter panels on the south wall of the shed vertically or am I just wasting them.

    Here are some pictures for your entertainment.....and yes that shed was built in 1995 with that penny fuse box lol. But it does have a concrete slab foundation.



    https://photos.app.goo.gl/HTyMdrgdiutjTBRz5

    The cell tower sweeps a shadow touching the shed roof only in January. But would definitely hit the ground mount all winter. You can look at my address on Google Earth and see 3343 S 30th Rd Humansville, MO 65674

    I also plan on becoming a lumberjack also I own the west to the highway and the east neighbor said have fun


    Last edited by mr2nr151; 11-28-2019, 10:45 AM.

  • #2
    My first question, is how do you manage to use 5 times as much power a year as I
    did before solar? Replacing obsolete AC equipment with state of the art (25-33 SEER)
    could cut cooling costs by half, and drastically cut any electric heating cost.

    Next thing I suppose you were going to connect solar power to the shed electric? An
    array in the range you describe will require AT LEAST a 4 gauge feed to the house, a
    2 gauge would be more efficient. Often these are only wired with 6 gauge.

    Facing panels E and W can work, that is what is going on here. Best with a string inverter,
    an E string and a W string connected to the same inverter, will hand off early and late
    harvesting all day instead of a single peak requiring larger plant (inverters and feeds) for
    the same total energy. And performance under clouds is boosted, trading here just more
    panels vs everything larger.

    Finally you can optimize panel use better and make DIY much easier with ground mount.
    good luck, Bruce Roe
    Last edited by bcroe; 11-28-2019, 11:49 PM.

    Comment


    • #3
      Thanks for the reply Bruce. To answer your first question its a 1.5 story with a basement. I have two A/C units and two young children who do not really understand money yet . I still try and remind them to turn off lights and shut the upstairs door but ya they are kids and love the baths :[. I do plan on adding more insulation and trying to fill all the holes but the house is really efficient as I really only need to run the A/C on days where the low only gets down to 70 for a week. I really like how dependable everything I have compared to my dads geothermal and all the other "high efficiency" systems I have seen. We also have a pool and I use a welder once in a while. We use Propane forced air heat on the main floor but the upstairs is all electric and since the kids are now utilizing those room more well no bueno.

      For the second concern the pole runs a buried cable to the house along the back of the shed (pretty sure it would have to be pretty bulky) then the power runs back to the shed from the meter on the house that where the small gauge wire would be. So putting the Invertors on the shed is the plan tied into the main feed for the house and shed so no we are not just using shed feed wiring.

      Three I understand the string runs but what about a few vertically mounted south facing panels anybody think it's a good idea bad idea? Angle mounts? Pergola roof? I really don't want to ground mount something so fragile. Where I'll be mowing around it and its almost a driveway now where it would be.

      Comment


      • #4
        You need to get some actual KWH numbers on your loads, to determine if improvement
        there is practical. Pool pumps are usually big consumers, AC next. My panels are mounted
        high enough to get under them with a mower. Might need a safety fence for people. Bruce Roe

        Comment


        • #5
          Originally posted by bcroe View Post
          My first question, is how do you manage to use 5 times as much power a year as I
          did before solar? Replacing obsolete AC equipment with state of the art (25-33 SEER)
          could cut cooling costs by half, and drastically cut any electric heating cost.

          Next thing I suppose you were going to connect solar power to the shed electric? An
          array in the range you describe will require AT LEAST a 4 gauge feed to the house, a
          2 gauge would be more efficient. Often these are only wired with 6 gauge.

          Facing panels E and W can work, that is what is going on here. Best with a string inverter,
          an E string and a W string connected to the same inverter, will hand off early and late
          harvesting all day instead of a single peak requiring larger plant (inverters and feeds) for
          the same total energy. And performance under clouds is boosted, trading here just more
          panels vs everything larger.

          Finally you can optimize panel use better and make DIY much easier with ground mount.
          good luck, Bruce
          What 25-33 SEER A/C systems do you speak of?

          Im stuck with the same dilemma as the OP, solar rep adds the rebate incentives to the cost and it's let's make a deal at the car sales lot. I really don't like the price/watt pricing. No matter what the sizing is 2kw or 20kw, they try to boil it down to that. No matter what your looking at its $1k+ per panel installed. If I can buy the panel for 200-250, The Inverter and AC work should be a fixed cost and then reasonable per panel cost but instead we deal with car sales tactics. DIY is not an option with local incentives and even utility requirements.

          East/West should be able to work but not at $40-50k 10year+ payback. And I doubt 15kw array is going to cover all of your usage. My estimate is 60-65% and yours is similar situation. Your system is likely to run at 70% efficiency. Another' reason why you need extra panels but at $1k per panel is just crazy. It's just daisy chaining another adjacent panel on the same rail.

          If you can DIY on the shed I would install all the panels on it and have an electrician wire the Inverter, disconnect, etc to the meter location. You want a Line Side connection and not go thru the panel.

          i prefer Solaredge DC distribution with Optimizers.

          315-335W panel 200-250ea
          Optimizer 70ea
          inverter 2-2.5k
          Iron ridge rail system

          Electrician can price the wire, conduit and AC stuff.

          Comment


          • #6
            Yes I know It will be cheaper to halfway DIY it but I really can't justify the headache if there is any issues with the system and the fun of hauling 40-50 panels up on the 18ft metal roof. They will garuntee power output so I should be safe there. Honestly I'm more interested in the verticle panel question. Is it feesible?

            Comment


            • #7
              Originally posted by hardwired
              What 25-33 SEER A/C systems do you speak of?
              In service here are Mitsubishi MSZ-FH09NA (31-33 SEER effective heating to -13F)
              and Fujitsu 15RLS3YH (25.3 SEER effective heating to -15F). There are many other
              units available besides these mini-splits. Do check the operating range, efficiency,
              and other numbers for a match to your situation. COP is a great measure if you can
              find it. A lot of look alike (and cheaper) units are not close to this performance,
              do not be taken in.

              With solar energy available, these units can not only cool, but cover a substantial
              part of beginning heating for no extra cost.

              Vertically (wall) mounted mounted panels do OK in winter at higher latitudes, producing
              power from sun and some from reflections off the snow, while being very easy to keep
              clear of snow (if you can reach them). They generally are pretty ineffective in summer
              though increased panel count can compensate. Bruce Roe

              Comment


              • #8
                Not sure what you mean by vertical. They need to be angle mounted in the direction of the sun. Use angle mounts for on top of a pergola or invert the mount to install on the side of a building awning style. Watch the wind performance.

                HH+Solar+Awning.jpg

                Comment


                • #9
                  Thanks hardwired!! Yes wind is the next obstacle. What are these rated are they just as expensive as ground mounts? I wouldn't want to mount them as close to the edges as shown and just do as many as possible with the one line. These look at just about 45 degrees.

                  Comment


                  • #10
                    Not sure about wind but one outfit didn't really want to do it. Said the structure is expensive supposedly took two days to build. Probably referring to a car port. IMO mostly scare tactics so he can install on the roof where he knows homeowners don't want to do and spells more $$$ for them.

                    A supply house mentioned they sold the mounts used to angle panels on flat roofs and customers just mounted it backwards on the side of a building. They were iron ridge system - I would call them and ask what kind of wind load the mounts can take on a flat or low pitch roof and also for some mounted on the side of a building. Ask for part numbers for the anchors, etc.

                    For fixed tilts . I think the angle mounts are limited in the angle maybe 30 degrees. I also saw where one application they build wood supports out of 2x3 or 2x6. Was good but wood frame probably moves and puts stress on glass and panel substrate.

                    Typically for fixed tilt mounting your latitude is the recommended angle. There are some calculators and YouTube videos.

                    i haven't found any mounts that are adjustable for large panels. This would be ideal if you can set the the tilt angle for summer and winter seasons.

                    Comment


                    • #11
                      This one does seasonable tilt change, but it took a lot more than 2 days to erect.
                      A really big advantage is snow rejection in winter vertical position. Bruce Roe

                      18ArrayR.JPG

                      Comment


                      • #12
                        Nice. looks like a pull pin with slot adjustments by sliding forward or back. What kind of adjustability range are you getting? Sees like a beech to adjust a long array like that. My thinking was independant panel mounts on the back in a single row, and adjust one at a time on a side wall. On the pergola top the same but space the rows to avoid self shading

                        Installers seem to be poo pooing the snow impact. Some years we get a lot of snow here but mostly it melts off in a couple of days. If it stays cold and cloudy and the panels are covered is there any heat the PV is generating to melt off the snow or going to need to shovel them off? I think I have 35 and 22 degree roof angles.

                        Comment


                        • #13
                          Ya that articulating ground mount is cool but not worth the extra $$ when I can just sweep off the snow from the ground. I bet it's really only adjusted twice a year once in the spring and once in the fall. I personally am probably going to heat my garage if the snow stays longer than a couple days . We really haven't had a bad snow yet in a looong time.
                          Last edited by mr2nr151; 12-02-2019, 05:15 PM.

                          Comment


                          • #14
                            Originally posted by hardwired View Post
                            Nice. looks like a pull pin with slot adjustments by sliding forward or back. What kind of adjustability range are you getting? Sees like a beech to adjust a long array like that. My thinking was independant panel mounts on the back in a single row, and adjust one at a time on a side wall. On the pergola top the same but space the rows to avoid self shading

                            Installers seem to be poo pooing the snow impact. Some years we get a lot of snow here but mostly it melts off in a couple of days. If it stays cold and cloudy and the panels are covered is there any heat the PV is generating to melt off the snow or going to need to shovel them off? I think I have 35 and 22 degree roof angles.
                            The array rests on 6 machine bearings (with grease fittings) located just above the center of
                            gravity (in the long slot). It is nearly balanced so you can move the tilting part with one hand,
                            though with 24 panels the top weighs nearly a ton. I just take out 6 bolts at the lower end of
                            the 6 lower braces (NOT on a windy day), the little red winch easily holds the new angle while
                            I put the 6 bolts back into different holes. Range is 90 deg, from full horizontal to full vertical.

                            I see very little tilt capability in consumer stuff. If the array has any size, multiple pivot supports
                            must be in a near perfect straight line. A light was used shining thu to adjust these.

                            Yes the installers do not talk about clouds or snow. Just read an ad saying panels work fine
                            under clouds. Guess they think 5 or 10% output is fine. When I started it took more than an
                            hour after each of a dozen and a half snow falls that winter, temperatures were frequently 20F
                            BELOW zero. Snow piling up in front of the array had to be moved farther away. This array
                            is completely above the snow but within easy reach, just tapping on every fourth panel is about
                            all clearing it takes.

                            Lots of owners just write off winter production, not here. I trade off a more expensive mount
                            to increase summer and winter output, while reducing snow clearing effort to a small minimum.

                            No, the panels are not going to generate any heat when covered with snow, the sun must see
                            something dark. Bruce Roe


                            Last edited by bcroe; 12-02-2019, 08:04 PM.

                            Comment


                            • #15
                              Bruce,

                              Hows 35 degrees fixed tilt on the roof work for snow self clearing - sliding off in moderate cold weather once the sun hits it.

                              Were you able to find any adjustable tilt mounts for single panels that would work on a pergola and side of the building. The tilt makes a difference that shouldn't be ignored.

                              Comment

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